MODEL PS-31 Power Supply

MODEL PS-31Power Supply

User Manual

9300-4437-00 Rev J 12/2007

POWER

THERMALOVERLOAD321FAULT

AUDIBLE

ALERT

ON

CHANNEL STATUSPROGRAM

LEVELCHANNELASSIGN

123

TW INTERCOM SYSTEMPOWER SUPPLYPS31

RTS SYSTEMS

PROPRIETARY NOTICE

The product information and design disclosed herein were originated by and are the property of Telex Communications, Inc. Telex reserves all patent, proprietary design, manufacturing, reproduction, use and sales rights thereto, and to any article disclosed therein, except to the extent rights are expressly granted to others.

COPYRIGHT NOTICE

Copyright 2007 by Telex Communications, Inc. All rights reserved. Reproduction, in whole or in part, without prior written permission from Telex is prohibited.

WARRANTY NOTICE

See the enclosed warranty card for further details.

CUSTOMER SUPPORT

Technical questions should be directed to:

Customer Service DepartmentRTS/Telex Communications, Inc.12000 Portland Avenue SouthBurnsville, MN 55337 USATelephone: 800-392-3497Fax: 800-323-0498

RETURN SHIPPING INSTRUCTIONS

Customer Service DepartmentTelex Communications, Inc. (Lincoln, NE)Telephone: 402-467-5321Fax: 402-467-3279Factory Service: 800-553-5992

Please include a note in the box which supplies the company name, address, phone number, a person to contact regarding the repair, the type and quantity of equipment, a description of the problem and the serial number(s).

SHIPPING TO THE MANUFACTURER

All shipments of product should be made via UPS Ground, prepaid (you may request from Factory Service a different shipment method). Any shipment upgrades will be paid by the customer. The equipment should be shipped in the original packing carton. If the original carton is not available, use any suitable container that is rigid and of adequate size. If a substitute container is used, the equipment should be wrapped in paper and surrounded with at least four (4) inches of excelsior or similar shock-absorbing material. All shipments must be sent to the following address and must include the Proof of Purchase for warranty repair. Upon completion of any repair the equipment will be returned via United Parcel Service or specified shipper, collect.

Factory Service DepartmentTelex Communications, Inc.8601 East Cornhusker Hwy.Lincoln, NE 68507 U.S.A.Attn: Service

This package should include the following:

Tableof

Contents

DESCRIPTION ................................................. 1DESCRIPTION .......................................................1

GENERAL ...................................................................1FEATURES .................................................................1STATUS INDICATORS ....................................................2INPUT POWER ..............................................................2INTERCOM CHANNEL CONNECTIONS ..........................2IMPEDANCE SELECTION ..............................................2

Installation ..............................................................3MECHANICAL INSTALLATION ................................3ELECTRICAL INSTALLATION ..................................3

OPERATION ..................................................... 5POWER-UP INDICATIONS ...................................5FAULT INDICATIONS ...........................................5THERMAL OVERLOAD .........................................5IMPEDANCE SELECT SWITCHES .......................5PROGRAM INPUT .................................................5

THEORY OF OPERATION ............................. 7GENERAL ...............................................................7AC TO DC CONVERSION .....................................7IMPEDANCE GENERATOR ..................................7PROGRAM INSERTION AMPLIFIER ...................8DISPLAY AND DIAGNOSTIC CIRCUITRY ..........8

CHANNEL STATUS INDICATORS ............................8FAULT INDICATOR ...................................................8THERMAL OVERLOAD .............................................8

MAINTENANCE ............................................. 11INTRODUCTION .................................................11GENERAL MAINTENANCE ................................11

SAFETY CONSIDERATIONS .................................. 11ACCESS .................................................................... 11CLEANING ............................................................... 11INPUT POWER SELECTION .................................. 12CHANNEL DC OUTPUT FUSE REPLACEMENT . 12

TEST PROCEDURES ...........................................12TEST EQUIPMENT .................................................. 12INITIAL INSPECTION ............................................. 12POWER-UP TEST .................................................... 12POWERED CHANNEL TEST .................................. 13FUNCTIONAL TEST OF ALL OUTPUTS ............... 144.4 TROUBLESHOOTING ....................................... 15

REPLACEMENT PARTS ............................... 17WHERE TO OBTAIN PARTS ...............................17 MECHANICAL PARTS .......................................18ELECTRICAL PARTS .........................................19

DIAGRAMS AND SPECIFICATIONS .......... 25Specifications ........................................................33

CHAPTER 1

DESCRIPTION

DESCRIPTION

GENERALThe Model PS31 supplies 32 volts regulated DC power to each of three intercom channels. It has short circuit and thermal overload protection, with automatic recovery when the fault is removed.

FEATURES

Program Input

There is a PROGRAM INPUT connector on the rear panel. A CHANNEL ASSIGN switch on the front panel assigns the program to any of the three channels. A LEVEL control adjusts the program level to the intercom channel.

1

Status IndicatorsThere is an audible alarm and a red FAULT indicator for current overload indication on any of the three channels. An AUDIBLE ALERT switch on the front panel turns the alarm on or off, but the FAULT indicator will continue to flash during current overload conditions. There is also a green status indicator for each channel. Each of these indicators will remain lit during normal operation, but will turn off during a channel current overload condition. Output current is automatically reduced during an overload, and normal operation is restored when the overload is removed.

Input PowerThe PS31 is available in two versions: one for 115 VAC operation and one for 230 VAC operation. A simple internal modification changes the operating voltage for 100 VAC or 200 VAC. A POWER on/off switch is provided on the front panel.

Intercom Channel ConnectionsIntercom channels are connected to the rear panel of the PS31. A variety of connector pin-outs is provided to accommodate individual system requirements.

Impedance SelectionThe PS31 provides the required channel terminating impedance for each channel. A 200/400 ohm IMPEDANCE SELECT switch for each channel is located on the rear panel. These switches are set to 200 ohms for normal operation. The 400 ohm setting permits two PS31's to be coupled to double the DC capacity of the system.

FIGURE 1. PS-31 Front and Back View

TELEX COMMUNICATIONS, INC.

MADE IN USA

TW INTERCOM SYSTEM

POWER SUPPLY

MODEL PS 31

NOTE

INTERNALLY

FUSED

CONNECTOR

PIN-OUT CODE

CH 1 - 2

PIN - 1 COM

PIN - 2 CH 1

PIN - 3 CH 2

CH 1 - 3

PIN - 1 COM

PIN - 2 CH 1

PIN - 3 CH 3

CH 2 - 3

PIN - 1 COM

PIN - 2 CH 2

PIN - 3 CH 3

CH 1 - 2 - 3

PIN - 1

PIN - 2 CH 2

PIN - 3 CH 3

PIN - 4 COM

CH 1OUTPUTS CONNECT TO

TW INTERCOM SYSTEM COMPONENTS

REFER TO OPERATION MANUAL

OUTPUTS

IMPEDANCE SELECT

CHANNEL

CH 1-2-3 CH 1-2-3 CH 1-2-3

PUSH

1 2 3

J107 J108 J109

J110

J111

AC POWER

J101 J102 J103 J104 J105 J106

CH 2-3CH 2-3CH 1-3CH 1-3CH 1-2CH 1-2

PROGRAM INPUT

Z = 10K BALANCED

PIN 1 - GROUNDED

PIN 2 - LO

PIN 3 - HI

400

DUAL

200

NORM

�

�CAUTION

WARNING

- TO REDUCE THE RISK OF FIRE, REPLACE ONLY WITH SAME TYPE FUSE

- TO REDUCE THE RISK OF FIRE OR ELECTRIC SHOCK, DO NOT EXPOSE THIS APPLIANCE TO RAIN OR MOISTURE

POWER

THERMALOVERLOAD321FAULT

AUDIBLE

ALERT

ON

CHANNEL STATUSPROGRAM

LEVELCHANNELASSIGN

123

TW INTERCOM SYSTEMPOWER SUPPLYPS31

RTS SYSTEMS

2

Installation

MECHANICAL INSTALLATIONThe Model PS31 can be rack mounted or used free standing. The rack mount is a standard 19-inches wide by 3.5-inches high. Allow room for cable connections.

ELECTRICAL INSTALLATION

CONNECTING INTERCOM STATIONS

NOTE: When connecting intercom stations, do not exceed the power supply capacity, either for one channel or for all three channels. Power supply capacity is graphically illustrated in Figure 1. If more capacity is required, refer to “PS 31 Capacity” on page 4.

Connect intercom channels to the OUTPUTS connectors on the rear panel. Pin assignments are printed above the connectors. These connectors provide three alternatives for intercom channel connection:

• Connectors J101 through J106 can be used to connect various combinations of two channels.• Connectors J107 and J108 can be used to connect all three channels.• Connector J109 can also be used to connect three channels, but unlike all the other connectors, no power is

supplied at this connector. This connector can be used to interconnect the audio channels when using two PS31 power supplies.

USING TWO PS31'S TO EXPAND CAPACITY

If there are more stations on one or more channels than the power supply capacity will allow, two PS31 power supplies may be used to double capacity. For each channel that requires added capacity:

1. Use the J109 connectors on both power supplies to interconnect the audio and ground pins of the desired channel (See “PS-31 Front and Back View” on page 2.).

2. Divide the stations that you wish to connect into two groups. Connect one group to the first power supply. Connect the other group to the second power supply. For each group, do not exceed the capacity (either total or per channel) of the power supply.

3. On both power supplies, set the IMPEDANCE SELECT switches for the channel to the 400<F128M>W<F255D> DUAL position. (Leave all impedance switches for channels that are not interconnected in the 200<F128M>W<F255D> NORM position.

PROGRAM INPUTS

A program source may be connected to the PROGRAM INPUT connector on the rear panel. Pin assignments are printed above the connector (See “PS-31 Front and Back View” on page 2.).

To connect an unbalanced program source, connect pin 2 to to pin 1. Then connect program ground to pin 1 and program HI to pin 3.

If two PS31's are interconnected, a separate program source may be connected to each.

AC POWER

Plug the AC power cord into the PS31 and into an AC mains outlet.

3

NOTE: The PS31 is factory-set for either 110-120-volt operation or 220-240-volt operation. The operating voltage is indicated on the back of the unit. Operation at 100-110 volts or 200-220 volts requires an internal modification. Refer to “MAINTENANCE” on page 11.

FIGURE 2. PS 31 Capacity

4

CHAPTER 2

OPERATION

POWER-UP INDICATIONSTurn on the POWER switch. During normal operation the three CHANNEL STATUS indicators should be lit and the FAULT and THERMAL OVERLOAD indicators should be off.

FAULT INDICATIONSIf there is a fault on a channel, the CHANNEL STATUS indicator for that channel will turn off and the red FAULT indicator will flash. If the AUDIBLE ALERT is set to “ON”, the alarm will beep. Possible causes of a fault include: overvoltage, overcurrent, short circuit to ground or severe brown-outs.

THERMAL OVERLOADIf the PS31 overheats, the THERMAL OVERLOAD indicator will turn on and AC power to the PS31 will be shut off. Normal operation will resume when the PS31 cools. Possible causes of a thermal shut-down include overloading the output channels or improper internal mains voltage selection.

IMPEDANCE SELECT SWITCHESThe IMPEDANCE SELECT switches on the rear panel allow each channel to be set for 200 ohm or 400 ohm operation. Select 200<F128M>W<F255D> NORM for each channel operated independently. Select 400<F128M>W<F255D> DUAL for each channel connected to another channel through the AUDIO ONLY connector (J109). Figure 1, “PS-31 Front and Back View,” on page 2

PROGRAM INPUTIf a program source is connected to the PROGRAM INPUT connector on the back of the PS31, it may be routed to any one of the intercom channels using the CHANNEL ASSIGN switch. Use the LEVEL control to adjust the program level on the selected channel.

5

6

CHAPTER 3

THEORY OF OPERATION

GENERALThe PS31 electronic circuits include an AC to DC converter, an impedance generator for each channel, a program insertion amplifier, and display and diagnostics circuits (Figure 3 on page 9). The following paragraphs describe these circuits. For schematic reference, see drawing SD3225 in Chapter 7.

AC TO DC CONVERSIONTransformer T101 steps down the AC mains voltage to 33 volts rms. Diodes D101-D104 rectify this voltage and capacitor C117 filters out the AC component, leaving about 45-50 volts unregulated DC. This raw DC voltage feeds the impedance generators (through fuses F201, F301, and F401), and regulator U101.

U101 provides regulated 30 volts DC. This voltage is supplied to the impedance generators, to the program insertion amplifier, and to U102. Diodes D109 and D110 protect U101. Resistors R107 and R108 establish the output voltage reference of 30 volts DC. Capacitor C121 reduces the amount of ripple on the 30 volts DC, and C122 provides decoupling.

U102 provides regulated 7.5 volts DC. This voltage is used as a reference level by the program insertion amplifier. It also powers the display circuits. Diodes D111 and D112 protect U102. Resistors R109 and R110 establish the output voltage reference of 7.5 volts. Capacitor C123 reduces the amount of ripple on the 7.5 volts DC and C124 filters the output.

IMPEDANCE GENERATORThere is a separate impedance generator for each channel. The impedance generator supplies regulated 32 volts DC to the channel and also provides the channel terminating impedance. The following paragraphs describe the impedance generator for channel 1. Other channels are identical.

Diodes D202 and D201 and resistors R202 and R201 divide the raw DC for the variable DC reference. This variable DC reference allows the quiescent output voltage of the regulators to follow the rms value of the AC mains voltage. Capacitors C202, C203 and C204 and resistors R203 and R206 are a low pass filter for the variable DC reference and provide fast start up response time. Integrated circuit U202B, resistors R214, R215 and R217 and capacitors C210 and C207 amplify and buffer the variable DC reference. Resistor R213 and capacitor C209 decouple the supply voltage for integrated circuit U202. Resistors R211 and R208 set the amount by which the output voltage of the regulator exceeds the variable DC reference. R205 sinks the quiescent current from R208. Diode D203 clamps excessive output voltage of the regulator due to transients while diodes D204 and D206 protect the regulator from reversed voltages due to shorts on the output line.

7

Resistors R219 and R221 sense the output current from the regulators into the RTS line. Integrated circuit U202A, together with capacitors C212 and C214 and resistors R220, R225, R223, and R216 differentially amplify this output current and feed it back to the adjust terminal of the regulators to create the audio impedance. Diodes D207, D208, D211, D212, D209, and D210 clamp the audio output voltage to avoid over-driving the RTS line and allow fast recovery from large transients.

Diode D214 protects the impedance generator from an over voltage on the RTS line. Capacitor C215 is an RF bypass and resistor R227 biases diode D214 on with 10 mA of current for “dry line” operation. Toggle switch S201, located on the rear panel selects an output impedance of 200 or 400 ohms. Since the impedance generator operates at 400 ohms, toggle switch S201 shunts the output with 390 ohms for a 200 ohm output.

PROGRAM INSERTION AMPLIFIERThe program-insertion amplifier circuitry accepts balanced or unbalanced input from any source and injects this input, via a bilateral current source, onto the RTS line.

Program audio, present at connector J110, rear panel, is applied via input isolation transformer T103 to PROGRAM LEVEL potentiometer R111. Resistor R606 and capacitor C601 provide RF suppression. Integrated circuit U601a, capacitor C602 and resistors R603 and R602 amplify the input and provide a low impedance drive for the following stage. Integrated circuit U601b, capacitor C606 and resistors R604, R607, R609, R605, and R608 form the bilateral current source which turns the input voltage into an output current. Capacitors C604, C605 and resistor R610 blocks any DC potential on the RTS line. Diodes D601 and D602 protect integrated circuit U601 from transients and resistor R601 and capacitor C603 decouple the power to integrated circuit U601.

DISPLAY AND DIAGNOSTIC CIRCUITRYThe display and diagnostic circuits detect fault conditions and warn the user with front panel lights and an audio indicator.

CHANNEL STATUS INDICATORS(The channel status indicator for channel is described. The channel status indicators for channels 2 and 3 are identical.)

As long as the output voltage on channel 1 is above approximately 21 VDC, diode D205 will conduct causing transistor Q201 to be on, which turns on DS201, the CHANNEL 1 STATUS LED on the front panel. If the channel 1 voltage drops below approximately 21 volts, transistor Q201 shuts off, LED DS201 goes dark, and the fault indicator circuitry is notified through diode D215.

FAULT INDICATORIf pin 5 of integrated circuit U103 is driven high by an under-voltage condition on any channel, the flasher circuit, which consists of half of integrated circuit U103, capacitor C126 and resistors R116 and R117, will flash the FAULT indicator LED, DS101, and pulse the audible alarm circuit. The audible alarm oscillator consists of the other half of integrated circuit U103, capacitor C127 and resistors R120 and R121.

THERMAL OVERLOADSwitch S101 is a thermal sensing switch connected in series with the power switch. It is attached to the power transformer, T101. The front panel THERMAL OVERLOAD indicator, DS5, is connected across S101. If the transformer temperature remains below approximately 75 C, S101 will remain closed, and there will be no voltage drop across DS5. If the transformer temperature rises above 75 C, S101 will open and remove AC primary power to T101. The AC voltage will be developed across DS5 and it will light.

8

FIGURE 3. Block Diagram

9

10

CHAPTER 4

MAINTENANCE

INTRODUCTIONThis section provides service information for normal maintenance, factory performance tests and troubleshooting tips.

GENERAL MAINTENANCE

SAFETY CONSIDERATIONSService and adjustments should be performed only by qualified service personnel.

Any adjustment, maintenance, and repair of the opened equipment while any power or voltage is applied should be avoided as much as possible, and should be carried out only by a skilled person who is aware of the hazard involved.

It is possible for capacitors inside the equipment to still be charged even if the equipment has been disconnected from its power source.

Be certain that only fuses with the required current rating and of the specified type (fast blow, time delay, slow blow, etc.) are used for replacement. The use of repaired fuses and the short-circuiting of fuse holders must be avoided.

ACCESSTo get inside the Model PS31, remove the screws on the top and bottom covers. Slide covers off toward the back of the unit.

CLEANINGClean the outside of the Model PS31 with denatured alcohol or a mild solution of detergent and water. Clean the interior with dry, low pressure air. The circuit boards can be cleaned with 1,1,1 trichloroethane or Freon TF. Do not allow these or any solvents to get into any potentiometers.

11

INPUT POWER SELECTION

CAUTION: These maintenance instructions are for qualified personnel only. To avoid electric shock, do not perform any servicing unless qualified to do so. Disconnect AC power before servicing.The Model PS31 operates on 100, 120, 200, or 240 volts AC at 50/60 hertz, depending on the internal power settings. To convert from one mains voltage to another, remove the covers and set the internal switch, jumpers and use the proper rear panel fuse as specified in Table 3. (The switch and jumpers are located on the circuit board next to the power transformer connector.)

CHANNEL DC OUTPUT FUSE REPLACEMENTTo replace channel fuses (F201, F301, F401), remove covers. These fuses are located on the circuit board.

TEST PROCEDURES

TEST EQUIPMENT• An isolated, variable voltage power transformer with voltage and current metering ("VARIAC",

"POWERSTAT", or equivalent)• A sine wave oscillator• An oscilloscope, 15 megahertz minimum bandwidth• A distortion analyzer (HP331 through HP334, HP339, or equivalent)• An AC voltmeter capable of reading volts, dBm and dBu• Two DC voltmeters• A test load (see Figure 4)• A capacitive load box (see Figure 5)• A program input cable (see Figure 6)• Two channel output cables (see Figure 7)

INITIAL INSPECTIONVerify electrical orientation of power supply capacitors. Verify proper wiring of transformer primary for local mains voltage. Verify that the proper fuses are installed in the back panel fuse holder and on the printed circuit board. Check that the transformer is securely mounted and that it is electrically isolated from the chassis (resistance from chassis to transformer core should be greater than 10 kohms). Check that the power supply capacitor is securely fastened. Using an ohmmeter, verify that the chassis is electrically connected to the grounding pin on the power connector (less than 0.2 ohm).

POWER-UP TEST1. Set the variable voltage power transformer to off, and set the voltage to zero.

TABLE 1. Voltage Selection

AC Source S107 Setting

Jumpers Rear Panel FuseAdd Remove

100 VAC 115 W2, W3 W1, W4 3A120 VAC 115 W1, W4 W2, W3 3A200 VAC 230 W2, W3 W1, W4 1.5A240 VAC 230 W1, W4 W2, W3 1.5A

12

2. Plug the PS31 into the variable voltage power transformer.3. Set the PS31 POWER switch to ON.4. Set the PS31 AUDIBLE ALERT switch to ON.5. Turn on the variable voltage power transformer.6. Slowly turn up the voltage. Watch for excessive sustained current consumption above 1 ampere. While the voltage is

being increased, the audible alert indicator should sound and the FAULT light should flash. Stop increasing the voltage when the standard operating voltage level is reached.

7. Set the AUDIBLE ALERT switch to off.8. Turn the PS31 POWER switch off: the STATUS lights should fade, and finally, the FAULT light should blink. The

audible alert should not sound.9. Turn the POWER switch back on.10. Turn the AUDIBLE ALERT switch on.

POWERED CHANNEL TESTThe following procedure tests channel 1. Repeat for channels 2 and 3.

1. Connect the DC meters and capacitive load to the test load as shown in Figure 5-1.2. Set the capacitive load to OFF.3. On the test load, set the output current potentiometer in the fully CCW position (minimum output load).4. Plug one of the four-wire channel output cables into J108 on the PS31. This will be the powered output cable5. Connect the ground lead of the powered output cable to the test load ground terminal.6. Connect channel 1 of the powered output cable to the powered channel terminal of the test load.7. Connect the second four-wire output cable to J109 on the PS31. This will be the AUDIO ONLY output cable.8. Connect channel 1 and ground of the audio only output cable to the distortion analyzer input and to the AC voltmeter.9. Connect the program input cable to the PS31 PROGRAM INPUT (J110) and to the sine wave oscillator.10. On the PS31, set the PROGRAM CHANNEL ASSIGN switch to channel 1. Turn the PS31 PROGRAM LEVEL

control fully CCW (minimum level).11. Set the sine wave oscillator for 1 kilohertz, 0.10 volt rms at the PROGRAM INPUT of the PS31.12. Observe the DC output voltage on DC voltmeter 1. It should be between 31.0 and 32.5 volts DC.13. Set the output current adjustment control on the test load so that the output current is 0.50 amperes (0.5 volts at DC

voltmeter 2). The output voltage at voltmeter 1 should drop by 0.5 volts or less.14. Adjust the PS31 PROGRAM LEVEL control fully CW (maximum level). The AC voltage should be 1.8 volts rms.15. Adjust the PROGRAM LEVEL control until the AC voltmeter reads 1.0 volt rms. The waveform on the scope should

be a sine wave with no hum or distortion.16. Set the capacitive load box switch to 100 pF. The waveform on the scope should remain unaffected. Repeat this step

for all the positions of the switch. The only noticeable effect should be waveform attenuation with the higher capacitance values.

17. Set the capacitive load to OFF.18. Set the oscillator frequency to 10 kilohertz (the oscillator level should remain constant). The AC voltage should read

between 0.79 and 1.0 volts rms.19. Set the oscillator frequency to 100 hertz (the oscillator level should remain constant). The AC voltage should read

between 0.71 and 0.89 volts rms. Return the oscillator frequency to 1 kilohertz.20. Place a 200-ohm resistor across the distortion analyzer input. The AC voltmeter should read from 0.45 to 0.55 volts

rms. Remove the 200-ohm resistor.21. Short the POWERED CHANNEL terminal of the test load to the SHORTING TERMINAL on the test load. The

output short circuit current should be 0.5 amp (0.5 volts at DC voltmeter 2), 30%. The channel 1 STATUS light should be extinguished, the FAULT light should be flashing, and the audible alert should sound. Remove the short. The FAULT light should go out and the channel 1 STATUS light should turn on.

13

22. On the test load, slowly turn the output current adjustment control CW. The output current (as measured at DC voltmeter 2) should slowly increase. The FAULT light and audible alert should again come on as the output voltage drops below approximately 21 volts (measured at DC voltmeter 1). The current will reach a maximum fold-back value of 2.0 amps (2.0 volts on voltmeter 2), 30% before falling very suddenly back to the short circuit value of 0.5 amps.

23. Turn the output current adjustment control on the test load fully CCW. The AC voltmeter should still read 1.0 to 1.1 volts rms and the waveform on the oscilloscope should be a sine wave free from distortion.

24. Turn the PROGRAM LEVEL control fully CCW. Read the hum and noise on the distortion analyzer meter using a low pass filter on the analyzer (approximately 30 kilohertz). The hum and noise should be less than 1.0 millivolt rms.

25. Repeat tests for PS31 output channels 2 and 3.

FUNCTIONAL TEST OF ALL OUTPUTSPlug a user station into each output connector. Verify that each station works.

FIGURE 4. Test Load

14

4.4 TROUBLESHOOTING

Figure 2. Capacitive Load Box

Figure 3. Program Input Cable

Figure 4. Channel Output Cable

Problem Check

No Output & No Lights

Plug, powerFuse, back panel (F105)Voltage SelectionExcessive transformer temperature (thermal cut-out will self reset after a cooling period.Raw DC supply voltage (should be 45-50 volts)

No Program

Input ConnectionsInput LEVEL control CHANNEL ASSIGN switch

Hum

Input ConnectionsIntercom cable routing (too close to AC, lights, etc.)User station too close to a power transformer.PS31 common lead connected to a “humming” chassis ground someplace.Mains voltage wiring incorrect.

Fault indicator ON

Short on intercom channelChannel overloaded“Brown-out” on mainsVoltage selection is set wrongBrown fuse on PCB (F201, F301, F401)DC voltage output (32 volts nominal)

Status OK, Yet NO Output

Check for AC on RTS line due to faulty power line wiring

Distorted Sound

Input connectionsPROGRAM LEVEL controlTerminationDC line voltage

15

16

CHAPTER 5

REPLACEMENT PARTS

WHERE TO OBTAIN PARTSParts may be obtained directly from RTS at:

Telex/RTS SystemsAttn: Factory Service1930 West 1st StreetBlue Earth, MN 56013Phone 1-507-526-3205Toll Free 1-800-218-2412

17

MECHANICAL PARTSReference AS3233 Drawing.

Mechanical Parts

Item No. Qty Description RTS Part No.

1 1 Front Panel/Chassis 9090-3232-00

21 Rear Panel (120V

version) 9080-3229-01

1 Rear Panel (220V version) 9080-3229-00

3 1

Printed Circuit Board Assy (Ref Section 6.3 for electrical parts)

9030-3225-00

4 2 Top/Bottom Cover 9030-3230-00

5 4 Transformer Bracket 9110-2629-00

6 1 Power Transformer (T101) 9140-2623-00

7 8 Washer, #6 Shoulder, Nylon 1006-0017-00

10 16 Screw, 4-40 X 3/8” 1008-4035-00

11 8 Screw, 6-32 X 1/4” Pan Head, Phil 1008-6038-00


13 4 Screw, 6-32 X 2” Pan Head, Phil 1008-8036-00


15 8 Washer, Lock, Int Th, #6 50014-001

16

17 8 Washer, Lock, Int Th, #8 50014-003

18 16 Nut, Keps, #4-40 51745-00019 4 Nut, Keps, #6-32 51745-00420 1 Nut, #6-32 1007-0003-002122 1 Knob, Gray 2703-0002-0023 1 Cap, Gray with Dot 2705-0001-00

24 1 Fuseholder, PCB Mount 2802-001-01

25 1 Fuseholder Cap 57074-006

18

ELECTRICAL PARTS

Electrical Parts

Item Qty Ref_Des Description Part Number

1 2W1 Resistor, O

Ohm, 1/4W 5%

52154-971W4

2 4

R217Resistor, 100 Ohm, 1/4W 5%

52154-305R317R417R609

3 3R122 Resistor, 1

KOhm, 1/4W 5%

52154-281R602R606

4 10

R203

Resistor, 10 KOhm, 1/4W 5%

52154-257

R206R218R303R306R318R403R406R418R603

5 6

R101

Resistor, 100 KOhm, 1/4W, 5%

52154-233

R102R103R115R123R610

6 1 R117Resistor, 1 MOhm, 1/4W, 5%

52154-209

7 1 R121Resistor, 11 KOhm, 1/4W, 5%

52154-256

8 1 R109Resistor, 1.3 MOhm, 1/4W 5%

52154-278

9 1 R119Resistor, 2.2 KOhm, 1/4W 5%

52154-273

10 7

R120


52154-249

R210R226R310R326R410R426

11 1 R116Resistor, 2.2 MOhm, 1/4W, 5%

52154-201

12 2R108 Resistor,

240 Ohm, 1/4W 5%

52154-296R110

13 3R204 Resistor, 2.7

Ohm, 1/4W 5%

52154-343R304R404


KOhm, 1W, 5%

52154-623R327R427


KOhm, 1/4W, 5%

52154-268R305R405

16 3R207 Resistor,

390 Ohm, 1/4W, 5%

52154-291R307R407

17 3R222 Resistor,

470 Ohm, 1/4W, 5%

52154-289R322R422

18 1 R114Resistor, 4.7 KOhm, 1/4W, 5%

52154-265

19 1 R118Resistor, 47 KOhm, 1/4W, 5%

52154-241

20 7

R212

Resistor, 47 Ohm, 1/4W, 5%

52154-313

R213R312R313R412R413R601

Electrical Parts


19

21 1 R107Resistor, 5.6 KOhm, 1/4W, 5%

52154-263

22 1 R113Resistor, 10 KOhm, 1/2W, 5%

52154-434

23 1 R111

Resistor, Var. Audio, 10 KOhm (Installed)

1406-0032-00

24 6

R220

Resistor, 100 Ohm, 1/4W 1%

54042-100

R225R320R325R420R425

25 6

R201


54045-100

R202R301R302R401R402

26 2R607 Resistor, 20

KOhm, 1/4W, 1%

54045-200R608

27 3R208 Resistor,

2.26 KOhm, 1/4W, 1%

54044-226R308R408

28 3R211 Resistor,

243 Ohm, 1/4W, 1%

54042-243R311R411

29 6

R216

Resistor, 42.2 KOhm, 1/4W, 1%

54045-422

R223R316R323R416R423

30 2R604 Resistor,

60.4 KOhm, 1/4W, 1%

54045-604R605

Electrical Parts


31 6

R214

Resistor, 47.5 KOhm, 1/4W, 1%

54045-475

R215R314R315R414R415

32 6

R219

Resistor, WW, 2 Ohm 5W 5%

1404-02R0-5I

R221R319R321R419R421

33 1 C607CAP. CER. DISC. RAD. 10pF/50V

52157-502

34 1 C602CAP. CER. DISC. RAD. 100PF/50V

52157-330

35 8

C109

CAP. CER. DISC. RAD. 1510-R103-2R

C110C113C114C125C215C315C415

36 3

C213 CAP. CER. DISC. 0.1UF/500V 20%

1510-R104-2QC313

C413

37 3C208 CAP. CER.

DISC. 220pF/50V

52157-534C308C408

38 1 C127

CAP. CER. MONO. 0.01 UF/50V

1511-R103-2I

Electrical Parts


20

39 7

C126

B SIZE BULK RPE121Z5U104M05V / SR205E104MAA

52676-113

C210C216C310C316C410C416

40 5

C122 CAP .22 UF/50V Z5U 20%, B SIZE BULK CERAMIC MONO MURATA ZR205E224MAA-AVX-KEMET

52676-115

C209C309C409

C603

41 1 C128CAP. ELEC. RAD. 1.0 UF / 50V

51821-106

42 12

C121

CAPACITOR, ELEC. RAD. 10 UF / 50V

51821-110

C123C202C203C204C302C303C304C402C403C404C606

43 4

C124 CAPACITOR, ELEC. RAD. 100 UF / 25 V

51821-524C206C306C406

44 3

C207 CAPACITOR, ELEC. RAD. 100 UF / 35 V

51821-529C307

C407

Electrical Parts


45 1 C117

CAPACITOR, CDS123U075V4C

1513-R129-6K

46 12

C102

CAP 22 UF 50V P10394TB-ND

51821-640

C103C104C212C312C412C214C314C414C217C317C417

47 3C123 CAP. CER.

DISC. 120 pF / 50 V

52157-531C311C411

48 2

C105 CAPACITOR, AC LINE, 2200 PF ECK-ATS222ME OR ECK-DRS222MEY

517003-003C106

49 1 C604CAP. ELEC. RAD 47 UF / 16 V

51821-068

50 1 C605CAP. ELEC. RAD 47 UF / 50 V

51821-534

51 1 C601

CAP. MYLAR 0.001 UF / 50 V

1514-R102-2L

Electrical Parts


21

52 7

D101

DIO. REC. 7 AMP MR752

1601-0752-00

D102D105D106D214D314D414

53 9

D211

DIODE 1N914B

1601-0914-0BT

D212D215D311D312D315D411D412D415

54 12

D109

DIODE REC. 1 AMP 1N4004

50745-005

D110D111D112D204D206D304D306D404D406D601D602

Electrical Parts


55 12

D207

DIODE, ZENER, 5.1 V, 5% 1N5231B MOT OR DIODES INC.

1601-5231-0BTM

D208D209D210D307D308D309D310D407D408D409D410

56 3

D201 DIODE, ZENER, 10 V, 5% 1N5240B

86266011D301

D401

57 6

D202

DIODE, ZENER, 20 V, 5% 1N5240B

1061-5250-0BT

D205D302D305D402D405

58 3

D203 DIODE, ZENER, 36 V 5% 1N5365B

1601-5365-0BT

D303

D403

59 4

Q101XSTR, NPN, 2N5210

1602-5210-00Q201Q301Q401

60 4

U101 IC, VOLTAGE REG., LM317HVK

1603-0009-00U201U301U401

61 1 U102

ADJ REG. 3 TERMINAL NATL LM317T

53290-000

62 1 U103IC CD4011UBE

1603-4011-00

Electrical Parts


22

63 4

U202IC NE5532N-ONLY

53295-000U302U402U601

64 1 S101

TERMAL CUT-OUT (INST. TOP ASSY LEV.)

1914-0001-00

65 1 S102

SWITCH, PWR, ON-OFF MARQUARDT 1802.1123

1912-0004-00

66 1 S104

SWITCH, TOGGLE, 3 POS. PC MT (INST. TOP ASSY LEV.)

1903-0051-00

67 1 S106

SWITCH, TOGGLE, SPDT PC MT (INST. TOP ASSY LEV.)

1903-0050-00

68 1 S107

SWITCH, SLIDE, DPDT, SWCRFT # 11A1101A

1902-0001-00

69 3S201 SW, C&K

#7101SPYAV2GE

1903-0016-00S301S401

70 1 J1CONNECTOR, AMP # 640445-8

57762-508

71 1 J2CONN MOLEX # 26-60-4020

57708-102

Electrical Parts


72 6

J101

CONN. AUDIO E3MRA

59892-001

J102J103J104J105J106

73 1 J111

AC ADAPTOR, SWCRFT #EAC333

2018-0012-00

74 3

J107 CONNECTOR, 4-PIN AUDIO, MALE

2018-0006-00J108

J109

75 1 J110

CONNECTOR,NEUTRIK #NC3FD-H

59893-001

76 1 T101PWR TRANSFORMER

9140-2623-00

77 1 T103XFMR MOUSER 42TM019

2306-0012-00

78 1 T105FUSE, LITTELFUSE # 313003

50547-161

79 3

F201 FUSE 3 AMP, BUSSMANN #AGC-3

50547-010F301

F401

80 1 LS-1

AUDIBLE ALERT (INST. TOP ASSY LEV.)

2605-0003-00

81 1 DS5

OVERHEAT INDICATOR LAMP

1805-0006-00

82 1 DS101

LED, RED (INST. TOP ASSY LEV.)

1801-0147-0R

Electrical Parts


23

83 3

DS201 LED,

GREEN (INST. TOP ASSY LEV.)

1801-0147-0GDS301DC401

84 1 PC1 BARE_PCB 9040-3225-00

85 6FUSE CLIP, LITTLEFUSE #102071

2802-0005-00

86 1 SOCKET 14-PIN 53041-300

87 4 SOCKET 8-PIN 53041-302

88 4 INSULATOR MICA 50587-000

89 8

INSULATOR WASHER KEYSTONE 3045

1006-0017-00

90 2 WASHER # 10 1006-0021-00

91 2

SCREW 10-32 X 1/4” SLOT CAD PLATED

1008-1002-00

92 8

LOCKWASHER #6 CAD PLATED

50014-001

93 8

SCREW 10-32 X 5/8” PHIL CAD PLATED

1008-6006-00

94 1 HEAT SINK 9180323100

95 1HEATSINK (IRC 7-362-BA)

4502000300

96 1 RIVET 50015-15097 17 SPACER 46293P1

98 14 PEM NUT 6-32 59832-003

99 8

PC RECPTACLE AMP 1-380758-0

2004-0008-00

Electrical Parts


100 2CRIMP TERMINAL #10

1005-0099-00

101 1 SOLDER LUG #4 1003-0004-00

102 2

CABLE TIE; PANDUIT # PLT4S-M

51709-002

103 1

WIRE #18 AWG TEFLON GREEN 2” LONG

2511-0110-00

104 AR WIRE, 18 AWG BUSS 50704-007

105 AR THERMAL GREASE 51741-000

106 AR SOLDER_PASTE SS360

Electrical Parts


24

CHAPTER 6

DIAGRAMS and SPECIFICATIONS

DRAWING Number Title

AS3225 P.C.B., Assembly, Power Supply, Model PS31

SD3225 Schematic Diagram, Power Supply, Model PS31, sheet 1 of 2

SD3225 Schematic Diagram, Power Supply, Model PS31, sheet 2 of 2

AS3233 Final Assembly, Model PS31

WD3525 Wiring Diagram, Model PS31

25

26

27

FIGURE 5. PCB, Assembly, Power Supply, Model PS 31

28

FIGURE 6. Schematic Diagram, Power Supply, Model PS 31 page 1

29

FIGURE 7. Schematic Diagram, Power Supply, Model PS 31 page 2

30

FIGURE 8. Final Assembly, Model PS 31

31

FIGURE 9. Wiring Diagram, Model PS 31

32

Specifications

Channels

Three

Connectors

Six XLR-3 type connectors (2 channel)

Three XLR-4 connectors (three channel)

One XLR-3 type connector (program input)

DC Output Voltage (each channel)

32 volts nominal

Line Terminating Impedance (each channel)

200 ohms, switchable to 400 ohms when operating two supplies in parallel

Output Current Ratings (per channel) (see also, Figure 1-1)

Max before fault indication:

1.5 amps

Sustained Overload 50° C ambient:

2.0 amps

Max before foldback limiting:

2.5 amps

Short circuit current:

0.5 amps

Startup current:

0.5 amps

Max Total Sustained Current (50° C ambient)

2.0 amps

Intercom Audio

Level

2 volts pp nominal

Head Room

6 dB minimum

Frequency Response

75 Hz to 20 kHz (-3 dB) unloaded

Signal to Noise and Hum Ratio (Ref to 2V pp)

-60 dB

Program Input

Balanced or unbalanced, transformer isolated, program assignable to channels 1-3

Program Input Sensitivity

28 dBm to +14 dBm (Ref. 600ohm) for 2 volts pp on RTS line

Program Input Impedance

10,000 ohms

Program Frequency Response (-3 dB)

100 Hz to 20 kHz input to RTS line.

Indicators

Channel STATUS

Three green LEDs

Channel FAULT

One red LED and one audible alarm

THERMAL OVERLOAD

One red NEON type

Switches

One PROGRAM CHANNEL ASSIGN switch:One AUDIBLE ALERT on/off switch; one POWER switch; three 200/400-ohm IMPEDANCE SELECT switches.

Temperature

0 - 50° C operating; 0 - 75° C storage

Power Requirements

Voltage

100, 120, 220, or 240 VAC, 50/60 Hz

Power

100 volt-amps

Fuses

AC Panel Fuse

100/120 volts - 3A slow blow; 200, 240 volts - 1.5A slow blow

Internal DC fuses (each channel)

6A fast blow

Dimensions

Height

3.5 inches (8.9 cm)

Width

19 inches (48.3 cm)

Depth

10.5 inches (26.7 cm)

Weight

14.5 pounds (6.6 kg)

33

Documents

MODEL PS-31 Power Supply